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Smart biomaterials for connective tissues regeneration
Hefka Blahnová, Veronika ; Filová, Eva (advisor) ; Maxová, Hana (referee) ; Motlík, Jan (referee)
Connective tissues are characterized by significant volume of extracellular matrix. Their main role is to provide a mechanical support and protection to other body organs. This thesis is focused on regeneration of bone, cartilage and osteochondral defect. In the experimental part we observed viability and differentiation of human mesenchymal stem cells. In vitro we evaluated the potential of PCL scaffold with addition of growth factors, bone xenograft with biomimetic peptides, collagen I composite with bioceramics and a titanium alloy with nanostructured surface. During following in vivo study, we implanted a cell-free scaffold made of PCL, calcium phosphate and IGF-1, bFGF, TGFβ1 and BMP-2 to osteochondral defect. Unfortunately, addition of growth factors resulted in pathological inflammatory process despite clear beneficial effect in vitro. Likewise, the biomimetic peptide sequences promoted osteogenic differentiation of human mesenchymal stem cells. Addition of certain bioceramics influenced the scaffold morphology in the manner of pore size. However, we did not observe any effect of the surface characteristics on cell behavior. The cells were influenced rather by certain material. On the other hand, surface modification of titanium scaffold by anodic oxidation revealed that the most suitable...
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Vascular and osseous cells in polymer structures for tissue engineering
Filová, Elena ; Bačáková, Lucie (advisor) ; Maxová, Hana (referee) ; Motlík, Jan (referee) ; Kromka, Alexander (referee)
Artificial vascular and bone prostheses are engineered as bioinert, not allowing cell attachment and growth. Our aim was to prepare materials based on natural and synthetic polymers that could modify the surface or create the bulk material of prostheses, and test their bioactivity in vitro. We prepared fibrin assemblies of various thicknesses and evaluated the adhesion, growth and differentiation of endothelial cells (EC) on these layers. We observed increased cell spreading on twodimensional fibrin assemblies and improved cell growth and maturation on thick fibrin gels. Fibrin coated with collagen I, or fibronectin, increased the adhesion area and the proliferation activity of vascular smooth muscle cells (VSMC). Synthetic polymers were based on an inert block copolymer of poly(DL-lactide) and polyethylene oxide (PDLLA-b-PEO) in which 5% or 20% of the PEO chains were grafted with Gly-Arg-Gly-Asp-Ser-Gly oligopeptide, a ligand for cell adhesion receptors. Grafting oligopeptide peptide to the cell non-adhesive copolymer restored adhesion and growth of VSMC, even in a serum-free medium. Synthetic polymers could therefore serve as artificial extracellular matrix analogues for vascular tissue repair and regeneration. Our study with human osteoblast-like MG 63 cells cultured in poly(lactic-co-glycolic acid)...
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Relation between the reperfusion of pulmonary arteries after an acute pulmonary embolism to the development of chronic thromboembolic pulmonary hypertension.
Mrózek, Jan ; Jansa, Pavel (advisor) ; Maxová, Hana (referee) ; Hutyra, Martin (referee)
Relation between the reperfusion of pulmonary arteries after acute pulmonary embolism to the development of chronic thromboembolic pulmonary hypertension Incomplete resolution of thromboemboli following acute pulmonary embolism (PE) is a key factor in development of chronic thromboembolic pulmonary hypertension (CTEPH). In our study, we evaluated the incidence, risk factors and clinical impact of incomplete reperfusion after acute PE. Study population and methods: 85 patients after the first acute PE were assessed clinically and by pulmonary scintigraphy and echocardiography at month 6, 12 and 24 after an acute PE. Results: Incomplete reperfusion was detected in 23.5 % of patients after 6 months, in 24.9 % of patients after 12 months and in 18.6 % of patients after 24 months. At month 6, patients with incomplete reperfusion were more obese when compared with patients with normal reperfusion BMI 30.8 vs 28.3 kg/m2 ; p=0.012) and their initial hemoglobin levels were higher (143.0 vs 136.0 g/l; p=0.012). Similar results were observed at month 12 - patients with residual perfusion defects were more obese (BMI 31.1 vs 28.5; p=0.016) with higher initial hemoglobin levels (144.0 vs 136.0; p=0.007). Patients with incomplete reperfusion at month 24 were significantly older (67.7 vs 55.0 years; p=0.02), their...
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Evaluation of influence of mechanical loading on differentiation of stem cells into smooth muscle cells
Pražák, Šimon ; Filová, Elena (advisor) ; Maxová, Hana (referee)
Cultivation of cells in bioreactors with mechanical load simulates the physiological conditions to which cells in the body are exposed. This technology has been used to induce the differentiation of stem cells from adipose tissue towards the phenotype of vascular smooth muscle cells, which can further serve to form vascular replacements. At present, there is no established strategy for cultivating stem cells while being exposed to mechanical stress. The main aim of this work was therefore to optimize the cultivation strategy and determine the ideal load parameters. Differentiation was analyzed by immunofluorescence of specific smooth muscle cell markers, α-actin and h1-calponin, which were quantified by Western blot. Extracellular matrix production was also detected by immunofluorescence staining. The outcome of this work is the establishment of ideal conditions of cell culture in a bioreactor with mechanical load, during which they differentiate into smooth muscle cells. Three types of scaffolds were used for cultivation; plasma treated glass, fibrin-coated glass and decelularized pericardium. Preliminary results show that smooth muscle differentiation was succesfully induced in human and porcine adipose tissue stem cells. Cells were analyzed after 3 and 7 days of culture. Developing a stem cell...
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The role of epoxyeicosatrienoic acids in blood pressure and renal function regulation in the experimental models of hypertension
Honetschlägerová, Zuzana ; Čertíková-Chábová, Věra (advisor) ; Zicha, Josef (referee) ; Maxová, Hana (referee)
Introduction: Epoxyeicosatrienoic acids (EETs) are converted by the enzyme soluble epoxid hydrolase (sEH) to the biologically inactive dihydroxyeicosatrienoic acids (DHETs). EETs are significantly involved in the control of blood pressure, they influence vascular tone and renal transport mechanism. sEH inhibitor reduce blood pressure by increasing the bioavailability of EETs in many models of hypertension. Aim of the study: To determine that sEH inhibitor decreases blood pressure and improves the renal function during the development of malignant hypertension in transgenic rats after the induction of the mouse renin gene. Methods: Hypertension in Cyp1a1-Ren-2 transgenic rats was induced through a dietary administration of the natural xenobiotic indole-3-carbinol (I3C, 0.3 %) for 3 and 11 days. I3C activates the renin gene. At the same time, during a three-day induction of hypertension, the inhibitor of nitric oxide synthase L-NAME (600 mg/l) was administered in drinking water. The sEH inhibitor c-AUCB was given in drinking water at a dose of 13 or 26 mg/l, starting 48 hours before the initiation of I3C and L-NAME administration. Radiotelemetric measurement of blood pressure was performed and renal excretory parameters were monitored in the conscious animals. The effects on renal hemodynamics and...
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Cardiac ischemic tolerance in rats subjected to adaptation to chronic hypoxia and physical exercise: the role of TNF-alpha.
Svatoňová, Anna ; Neckář, Jan (advisor) ; Maxová, Hana (referee) ; Szárszoi, Ondrej (referee)
Cardiovascular diseases represent the most important health risk factors because they are responsible for more than 50% of total mortality. Among them, the ischemic heart disease is leading cause of mortality. From the whole spectrum of different cardioprotective phenomena we have selected: 1) adaptation to chronic normobaric hypoxia (CNH) as the traditional experimental model in our laboratory area and 2) protective effect of exercise which in recent years represents promising and clinically relevant protective mechanism. The whole thesis is based on two studies. Aim of the first study was to characterize the expression of the main pro-inflammatory cytokine, TNF-α, in hearts of rats adapted to CNH. Chronic TNF-α inhibition by infliximab was used for discovering of certain role of TNF-α in CNH. We showed that increased myocardial level of TNF-α during adaptation to CNH was contributed via its receptor TNFR2 and nuclear factor κB-dependent activation of protective redox signalling with increased antioxidant defence. This adaptive pathway participates on the infarct size-limiting effect of CNH. Aim of the second study was find out whether exercise training and CNH could play synergy in cardiac protection in rats model. We reported that CNH and exercise reduced infarct size but their combination...
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Vascular and osseous cells in polymer structures for tissue engineering
Filová, Elena ; Bačáková, Lucie (advisor) ; Maxová, Hana (referee) ; Motlík, Jan (referee) ; Kromka, Alexander (referee)
Artificial vascular and bone prostheses are engineered as bioinert, not allowing cell attachment and growth. Our aim was to prepare materials based on natural and synthetic polymers that could modify the surface or create the bulk material of prostheses, and test their bioactivity in vitro. We prepared fibrin assemblies of various thicknesses and evaluated the adhesion, growth and differentiation of endothelial cells (EC) on these layers. We observed increased cell spreading on twodimensional fibrin assemblies and improved cell growth and maturation on thick fibrin gels. Fibrin coated with collagen I, or fibronectin, increased the adhesion area and the proliferation activity of vascular smooth muscle cells (VSMC). Synthetic polymers were based on an inert block copolymer of poly(DL-lactide) and polyethylene oxide (PDLLA-b-PEO) in which 5% or 20% of the PEO chains were grafted with Gly-Arg-Gly-Asp-Ser-Gly oligopeptide, a ligand for cell adhesion receptors. Grafting oligopeptide peptide to the cell non-adhesive copolymer restored adhesion and growth of VSMC, even in a serum-free medium. Synthetic polymers could therefore serve as artificial extracellular matrix analogues for vascular tissue repair and regeneration. Our study with human osteoblast-like MG 63 cells cultured in poly(lactic-co-glycolic acid)...
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